Danshen extract circumvents drug resistance and represses cell growth in human oral cancer cells.

BACKGROUND: Danshen is a common traditional Chinese medicine used to treat neoplastic and chronic inflammatory diseases in China. However, the effects of Danshen on human oral cancer cells remain relatively unknown. This study investigated the antiproliferative effects of a Danshen extract on human oral cancer SAS, SCC25, OEC-M1, and KB drug-resistant cell lines and elucidated the possible underlying mechanism. METHODS: We investigated the anticancer potential of the Danshen extract in human oral cancer cell lines and an in vivo oral cancer xenograft mouse model. The expression of apoptosis-related molecules was evaluated through Western blotting, and the concentration of in vivo apoptotic markers was measured using immunohistochemical staining. The antitumor effects of 5-fluorouracil and the Danshen extract were compared. RESULTS: Cell proliferation assays revealed that the Danshen extract strongly inhibited oral cancer cell proliferation. Cell morphology studies revealed that the Danshen extract inhibited the growth of SAS, SCC25, and OEC-M1 cells by inducing apoptosis. The Flow cytometric analysis indicated that the Danshen extract induced cell cycle G0/G1 arrest. Immunoblotting analysis for the expression of active caspase-3 and X-linked inhibitor of apoptosis protein indicated that Danshen extract-induced apoptosis in human oral cancer SAS cells was mediated through the caspase pathway. Moreover, the Danshen extract significantly inhibited growth in the SAS xenograft mouse model. Furthermore, the Danshen extract circumvented drug resistance in KB drug-resistant oral cancer cells. CONCLUSION: The study results suggest that the Danshen extract could be a potential anticancer agent in oral cancer treatment.

Enhanced anti-tumor activity of triptolide in combination with irradiation for the treatment of oral cancer.

Advanced oral cancer has a poor prognosis because of the lack of an effective treatment. We explored the efficiency of combined treatment with triptolide and ionizing radiation for treating oral cancer. Human tongue cancer cells were treated with triptolide, ionizing radiation, or triptolide plus ionizing radiation. Cell proliferation, cell cycle arrest, and apoptotic influences were analyzed by FACS and immunohistochemistry. Tumor potency was examined in an in vivo human tongue cancer cells xenograft mouse model. Our results demonstrated that triptolide caused a marked reduction in colony number that was further enhanced with increasing doses of ionizing radiation. Triptolide increased apoptosis and decreased the expression of anti-apoptotic proteins. In vivo, combination treatment synergistically reduced tumor weight and volume possibly via the induction of apoptosis and reduction in anti-apoptotic protein expression. In conclusion, triptolide plus ionizing radiation treatment had synergistic anti-tumor effects, especially in vivo, and may be a promising combined modality therapy for advanced oral cancer.

α-Lipoic acid enhances endogenous peroxisome-proliferator-activated receptor-γ to ameliorate experimental autoimmune encephalomyelitis in mice.

ALA (α-lipoic acid) is a natural, endogenous antioxidant that acts as a PPAR-γ (peroxisome-proliferator-activated receptor-γ) agonist to counteract oxidative stress. Thus far, the antioxidative and immunomodulatory effects of ALA on EAE (experimental autoimmune encephalomyelitis) are not well understood. In this study, we found that ALA restricts the infiltration of inflammatory cells into the CNS (central nervous system) in MOG (myelin oligodendrocyte glycoprotein)-EAE mice, thus reducing the disease severity. In addition, we revealed that ALA significantly suppresses the number and percentage of encephalitogenic Th1 and Th17 cells and increases splenic Treg-cells (regulatory T-cells). Strikingly, we further demonstrated that ALA induces endogenous PPAR-γ centrally and peripherally but has no effect on HO-1 (haem oxygenase 1). Together, these data suggest that ALA can up-regulate endogenous systemic and central PPAR-γ and enhance systemic Treg-cells to inhibit the inflammatory response and ameliorate MOG-EAE. In conclusion, our data provide the first evidence that ALA can augment the production of PPAR-γ in vivo and modulate adaptive immunity both centrally and peripherally in EAE and may reveal further antioxidative and immunomodulatory mechanisms for the application of ALA in human MS (multiple sclerosis).